Moskowitz 9526812 The PI's propose to investigate the interrelation between micromagnetic structure and macroscopic magnetic behavior in magnetite, maghemite, and phase-coupled particles using magnetic force microscopy and magnetic property measurements. The magnetic force microscope (MFM) is a high-resolution magnetic robe that can image micromagnetic structures on a submicron scale. Magnetic oxide articles to be studied with the MFM will be produced using molecular-beam epitaxy and photolithography. These advanced microfabrication techniques can synthesize single crystalline, single phase and phase-coupled particles with precise control over shape, size, and crystallographic orientations. In this way, a systematic study of intrinsic domain patterns, domain wall structures, and other micromagnetic features as a function of particles size and crystallographic orientation within the pseudo-single domain (PSD) size range for magnetite (0.5-10 micrometer) will be accomplished. This experimental program will provide critical experimental testing of theoretical micromagnetic models, provide new and important data on micromagnetic structures and rock magnetic properties of phase-coupled CRM samples, and advance our understanding of the physical basis of paleomagnetism.
